Real-time monitoring identifies a firmware write command targeting a specific Input/Output (I/O) module slot address within a controller chassis from a source not in the approved engineering workstation list, distinguishing module-level firmware modification from main-processor firmware updates by its slot-addressed targeting. OT operational-fidelity gate: Alert only when the action is not attributable to an authorized operator/engineering source for the specific target and function, and it is either outside an approved change/maintenance window or lacks matching change-control context; where telemetry permits, require corroborating device, configuration, or process-state effect. Suppress activity that fully matches approved maintenance, commissioning, failover, recovery, or tested control procedures.
| Data Component | Name | Channel |
|---|---|---|
| Firmware Modification (DC0004) | assetinventory:FirmwareHash | module-specific firmware hash post-write does not match authorized module firmware inventory |
| Network Traffic Content (DC0085) | NSM:Content | firmware write service targeting specific slot/rack address from source not in engineering workstation list outside change control window |
| Field | Description |
|---|---|
| AuthorizedModuleFirmwareInventory | Hash inventory of authorized firmware versions per I/O module type and slot position. |
| ChangeControlWindow | Scheduled maintenance periods during which module firmware updates are authorized. |
| EngineeringWorkstationList | IP allowlist of workstations authorized to perform module-level firmware updates. |